GHz LSPR Modulation in Plasmonic Double-Resonance Nanoantennas due to Coherent Acoustic Vibrations

The ability to modulate localized surface plasmon resonances in noble metal nanostructures using coherent acoustic vibrations opens up novel opportunities for optical communication by enabling fast and precise control over light signals at the nanoscale. However, plasmonic nanostructures designed for operation in the optical C/L band, such as single gold nanobars, are relatively large, leading to low vibration frequencies of only a few GHz. To overcome this limitation, near-field coupled plasmonic systems provide an alternative, offering more design flexibility and higher vibration frequencies through the integration of differently sized elements. This paper characterizes a plasmonic double-resonance nanoantenna that leverages this feature, with preliminary results demonstrating the feasibility of transmitting highfrequency vibration states into the optical communication band.